1/* Internal function for converting integers to ASCII.
2 Copyright (C) 1994-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _ITOA_H
20#define _ITOA_H
21
22#include <limits.h>
23
24/* When long long is different from long, by default, _itoa_word is
25 provided to convert long to ASCII and _itoa is provided to convert
26 long long. A sysdeps _itoa.h can define _ITOA_NEEDED to 0 and define
27 _ITOA_WORD_TYPE to unsigned long long int to override it so that
28 _itoa_word is changed to convert long long to ASCII and _itoa is
29 mapped to _itoa_word. */
30
31#ifndef _ITOA_NEEDED
32# define _ITOA_NEEDED (LONG_MAX != LLONG_MAX)
33#endif
34#ifndef _ITOA_WORD_TYPE
35# define _ITOA_WORD_TYPE unsigned long int
36#endif
37
38
39/* Convert VALUE into ASCII in base BASE (2..36).
40 Write backwards starting the character just before BUFLIM.
41 Return the address of the first (left-to-right) character in the number.
42 Use upper case letters iff UPPER_CASE is nonzero. */
43
44extern char *_itoa (unsigned long long int value, char *buflim,
45 unsigned int base, int upper_case) attribute_hidden;
46
47extern const char _itoa_upper_digits[];
48extern const char _itoa_lower_digits[];
49#if IS_IN (libc) || IS_IN (rtld)
50hidden_proto (_itoa_upper_digits)
51hidden_proto (_itoa_lower_digits)
52#endif
53
54#if IS_IN (libc)
55extern char *_itoa_word (_ITOA_WORD_TYPE value, char *buflim,
56 unsigned int base,
57 int upper_case) attribute_hidden;
58#else
59static inline char * __attribute__ ((unused, always_inline))
60_itoa_word (_ITOA_WORD_TYPE value, char *buflim,
61 unsigned int base, int upper_case)
62{
63 const char *digits = (upper_case
64 ? _itoa_upper_digits
65 : _itoa_lower_digits);
66
67 switch (base)
68 {
69# define SPECIAL(Base) \
70 case Base: \
71 do \
72 *--buflim = digits[value % Base]; \
73 while ((value /= Base) != 0); \
74 break
75
76 SPECIAL (10);
77 SPECIAL (16);
78 SPECIAL (8);
79 default:
80 do
81 *--buflim = digits[value % base];
82 while ((value /= base) != 0);
83 }
84 return buflim;
85}
86# undef SPECIAL
87#endif
88
89/* Similar to the _itoa functions, but output starts at buf and pointer
90 after the last written character is returned. */
91extern char *_fitoa_word (_ITOA_WORD_TYPE value, char *buf,
92 unsigned int base,
93 int upper_case) attribute_hidden;
94extern char *_fitoa (unsigned long long value, char *buf, unsigned int base,
95 int upper_case) attribute_hidden;
96
97#if !_ITOA_NEEDED
98/* No need for special long long versions. */
99# define _itoa(value, buf, base, upper_case) \
100 _itoa_word (value, buf, base, upper_case)
101# define _fitoa(value, buf, base, upper_case) \
102 _fitoa_word (value, buf, base, upper_case)
103#endif
104
105#endif /* itoa.h */
106

source code of glibc/sysdeps/generic/_itoa.h